How Do You Calculate A Lower Quartile?
When statistically analyzing lists of numbers, it is often necessary to identify key values. These values include the minimum, maximum, median and the lower and upper quartiles. The lower quartile divides the first 25 percent of the data set from the following 75 percent. The method of determining the lower quartile is quite simple and yet fundamental to statistical understanding. Arrange your number set from smallest to largest. Determine the minimum or smallest number in the set. Note the minimum. Determine the median or the central number in the set. If there is an odd number of numbers, the one in the center is the median. If there is an even number of numbers, take the 2 central numbers, add them together, and divide them by 2 to find the median. Note the median. Add together the minimum and the median. Divide the result by 2. The result is the lower quartile.